Table 2.
Participants’ baseline physical activity characteristics stratified by group.
| Physical activity characteristics | Total sample (N=45) | Group 1: G4GPA2 (n=15) | Group 2: PA4GPA2 (n=15) | Group 3: GPA6 (n=15) | |||||
| Fitbit | ActiGraph | Fitbit | ActiGraph | Fitbit | ActiGraph | Fitbit | ActiGraph | ||
|
| |||||||||
| Number of valid days, mean (SD) | 6.7 (0.7) | 6.6 (0.7) | 6.8 (0.8) | 6.8 (0.8) | 6.5 (0.8) | 6.5 (0.7) | 6.8 (0.4) | 6.5 (0.6) | |
| Valid day, n (%); cumulative % | |||||||||
|
|
7 | 36 (80); 80 | 31 (69); 69 | 14 (93); 93 | 14 (93); 93 | 10 (67); 67 | 9 (60); 60 | 12 (80); 80 | 8 (53); 53 |
|
|
≥6 | 7 (16); 96 | 10 (22); 91.1 | 0 (0); 93 | 0 (0); 93 | 4 (27); 93 | 4 (27); 87 | 3 (20); 100 | 6 (40); 93 |
|
|
≥5 | 0 (0); 96 | 3 (7); 98 | 0 (0); 93 | 0 (0); 93 | 0 (0); 93 | 2 (13); 100 | 0 (0); 100 | 1 (7); 100 |
|
|
≥4 | 2 (4); 100 | 1 (2); 100 | 1 (7); 100 | 1 (7); 100 | 1 (7); 100 | 0 (0); 100 | 0 (0); 100 | 0 (0); 100 |
| Wear time (minute/day), mean (SD) | 865.1 (69.6) | 861.5 (86.9) | 912.4 (63.3) | 911.4 (88.5) | 832 (61.1) | 833.2 (74) | 851 (60.7) | 839.8 (80) | |
| Counts per valid wear minute, mean (SD) | —a | 328.7 (144.6) | — | 342.2 (107.6) | — | 281.3 (123.1) | — | 362.5 (187.5) | |
| Step count per day, mean (SD) | 8575 (4530) | 6905 (3776) | 9329 (4251) | 7331 (3433) | 7650 (4007) | 5637 (1963) | 8747 (5367) | 7748 (5148) | |
| Sedentary (minute/day), mean (SD) | — | 540.1 (95.3) | — | 569.9 (90.1) | — | 536.6 (89.9) | — | 513.9 (103.2) | |
| Light physical activity (minute/day), mean (SD) | — | 288.2 (83.4) | — | 304.4 (97.1) | — | 271.4 (77.3) | — | 288.7 (76.7) | |
| MVPAb (minute/day), mean (SD) | — | 33.1 (28.4) | — | 37 (21.2) | — | 25.2 (18.6) | — | 37.2 (40.5) | |
| MVPA in bouts ≥10 min (minute/day), mean (SD) | — | 10.1 (21.9) | — | 9.6 (14.4) | — | 5 (6.2) | — | 15.8 (34.5) | |
| Met physical activity guidelinesc, n (%) | — | 5 (11) | — | 2 (13) | — | 1 (7) | — | 2 (13) | |
| Active minutesc,d, mean (SD) | 39.8 (41.5) | — | 39.5 (28.2) | — | 43.5 (54.1) | — | 36.9 (42.9) | — | |
| Number of floors climbedd, mean (SD) | 11.8 (9.5) | — | 13.8 (8.2) | — | 7 (6.4) | — | 13.8 (11.7) | — | |
| Reminders to moved,e,f, mean (SD) | 3.6 (1.5) | — | 3.3 (1.7) | — | 3.9 (1.6) | — | 3.6 (1.2) | — | |
aNot available from the device.
bMVPA: moderate-to-vigorous physical activity.
cActive minutes are calculated by Fitbit’s undisclosed proprietary algorithm but are said to represent activity of ≥3 Metabolic Equivalent of Task (METS) and are only awarded if duration of activity is ≥10 consecutive minutes.
dActiGraph accelerometers do not capture a comparable variable.
eReminders to move track hourly step counts, and notifications delivered with a slight vibration are sent when the user does not reach 250 steps by 50 minutes of each hour (between 09:00 am-5:00 pm).
fNo notifications were active during this wear period; this intends to suggest how many would have been shown had the settings been unmasked.